code: def test_str_split_no_warning(index):
      df = pd.DataFrame({"a": ["a\nb"]}, index=index)
      ddf = dd.from_pandas(df, npartitions=1)
  
      pd_a = df["a"].str.split("\n", n=1, expand=True)
      dd_a = ddf["a"].str.split("\n", n=1, expand=True)
  
      assert_eq(dd_a, pd_a)
  
imports: from __future__ import annotations
  import contextlib
  import numpy
  import pytest
  import dask.dataframe
  from dask.dataframe._compat import PANDAS_GE_140, PANDAS_GE_210
  from dask.dataframe._pyarrow import to_pyarrow_string
  from dask.dataframe.utils import assert_eq, pyarrow_strings_enabled
label_desc: Use image node_id 17 for calling a global function with example usage: test_str_split_no_warning(index) without return types